Where do diamonds come from? Before a diamond is set and sold, it travels through a series of forms, and simultaneously, across the world. Diamonds are mined and initially traded as rough diamonds, then cut and polished to be traded as loose polished diamonds, sold to jewelry manufacturers where they become mounted polished diamonds, enter jewelry retailers, and are ultimately bought by consumers. Diamonds may be mined in Africa, cut and polished in India, traded in Belgium, and sold to consumers in the United States.